Highest temperature in Madrid on August 2?

Platform comparison

Market context

Madrid’s hottest reading on 2 August will be taken from the airport station at Adolfo Suárez Madrid-Barajas, and the market is currently pricing a distinctly warm but not extreme outcome, with 36°C and 37°C the clear crowd favourites while 0% for YES implies the contract is being treated as effectively impossible at present. That looks out of step with the broader market view for a standard midsummer Madrid peak, where the airport’s historical August climate is hot enough that mid-30s daytime highs are normal, but the exact resolution depends on the single highest observation recorded at the station rather than the day’s average temperature.[4][2][13]

For context, Madrid’s airport has a long record of occasional severe heat, but the most relevant comparison for traders is how often the city lands in a narrow band around the mid-30s rather than pushing far beyond it. AccuWeather’s August pages show typical highs around 90°F/32°C and historical averages in the low-to-mid 30s, while Madrid’s broader climate references note that the airport has reached 42.7°C in past extremes, underlining that a 36-37°C finish is plausible without requiring an exceptional heatwave.[1][5][9] That makes the current pricing look more like a consensus on an ordinary hot day than a bet on record-breaking heat.[4]

The main catalysts are the short-range temperature forecasts and any late changes in heat advisories for central Spain, especially if a subtropical ridge strengthens or weakens over the Iberian Peninsula. AccuWeather had already issued a yellow warning for extreme high temperatures in the Madrid metropolitan area, pointing to a maximum of 36°C, and Euronews reported forecasts earlier this year that placed Madrid near 36°C during a similar hot spell, which is the kind of setup traders will compare against the airport’s realised hourly peak.[3][20] Because the market resolves on the single highest airport reading, cloud cover, wind shifts, and the timing of the daily heat maximum matter more than the headline city forecast.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.